Cranial Nerves

12 pairs in total-all originate from brain except for spinal accessory nerve

(LPK-trOI-AFA-GVAH)

general somatic afferent(GSA)- V,VII,IX,X

general visceral afferent(GVA)-IX,X

special afferent(SA)-I,II,VII,VIII,IX,X

general somatic efferent(GSE)-motor III, IV, VI, XI,XII

general visceral efferent(GVE)-III,VII,IX,X

branchial efferent (BE)-V,VII,IX,X-motor to skeletal muscles derived from pharyngeal arch mesoderm

• Olfactory-SA- exit through cribriform plate of ethmoid bone -smell-
• Optic-SA -exit thru optic canal -vision
• Occulomotor-superior orbital fissure-

1. GSE-innervates levator palpebrae superioris,superior rectus,inferior rectus,medial rectus,inferior oblique (LR6SO4rest3)
2. GVE-innervates sphincter pupillae for pupillary constriction,ciliary muscles for accomodation of lens for near vision

• Trochlear-superior orbital fissure-GSE-superior oblique muscles
• Trigeminal-superior orbital fissure-ophthalmic division(V1), foramen rotundum-maxillary nerve(V2), foramen ovale-mandibular division(V3)

1. GSA-sensory from:V1(ophthalmic division)-eyes, conjunctiva, orbital contents, nasal cavity, frontal sunus, ethmoidal sinus, upper eyelid, dorsum of nose, anterior part of scalp, dura in anterior cranial fossa, superior part of tentorium cerebelli -------------V2(maxillary nerve)-dura in middle cranial fossa, nasopharynx, palate, nasal cavity, upper teeth, maxillary sinus, skin covering the side of nose, lower eyelid, cheek, upper lip------V3(mandibular division)-skin of lower face, cheek, lower lip, anterior part of external ear, part of external acoustic meatus, temporal fossa, anterior 2/3rd of tongue, lower teeth, mastoid air cells, mucous membranes of cheek, mandible, dura in middle cranial fossa
2. BE- innervates temporalis, masseter, medial & lateral pterygoids, tensor tympani, tensor veli palatini, anterior belly of digastric, myohyoid muscles

• Abducent-superior orbital fissure- GSE- innervates lateral rectus muscle
• Facial-stylomastoid foramen(nerve leaves cranial cavity through internal acoustic meatus)

1. GVA-sensory from part of external acoustic meatus & deeper parts of auricle
2. SA-taste from ant2/3rd of tongue
3. GVE-innervates lacrimal gland, submandibular & sublingual salivary glands & mucous membranes of nasal cavity, hard & soft palates
4. BE-innervates muscles of face(muscles of facial expression) & scalp derived from the second pharyngeal arch & stapedius, posterior belly of digastric, stylohyoid muscles

• Vestibulocochlear-nerve leaves cranial cavity through internal acoustic meatus- vestibular division-balance, cochlear-hearing
• Glossopharyngeal-jugular foramen

1. GVA-sensory from carotid body & sinus
2. GSA-posterior 1/3rd of tongue, palatine tonsils, oropharynx, mucosa of middle ear & pharyngotympanic tube
3. SA-taste from posterior 1/3rd of tongue
4. GVE-innervates parotid salivary gland
5. BE-innervates stylopharyngeus muscle

• Vagus-jugular foramen-

1. GSA-sensory from larynx, laryngopharynx, deeper parts of auricle, part of external acoustic meatus & dura in posterior cranial fossa
2. GVA-sensory from aortic body chemoreceptors & aortic arch baroreceptors, esophagus, bronchi, lungs, heart & abdominal viscera of the foregut & midgut
3. SA-taste from epiglottis & pharynx
4. GVE-innervates smooth muscle & glands in the pharynx, larynx, thoracic viscera & abdominal viscera of the foregut & midgut
5. BE-innervates one tongue muscle(palatoglossus), muscles of the soft palate ( except tensor veli palatini), pharynx (except stylopharyngeus) & larynx

• Accessory-jugular foramen-GSE-innervates sternocleidomastoid & trapezius muscle
• Hypoglossal-hypoglossal canal-GSE-innervates hypoglossus, genioglossus & styloglossus muscles & all intrinsic muscles of tongue